Pump safety switch



Nov. 14, 1961 c. A. DAVIS 3,008,420

PUMP SAFETY SWITCH Filed May 14, 1957 2 Sheets-Sheet 1 NOV. 14, 1961 C. A, DAvls 3,008,420

PUMP SAFETY SWITCH Filed May 14, 1957 2 Sheets-Sheet 2 Fig. 4

C/yne A. Davis mVENToR.

3,008,420 Patented Nov. 14, 1'961 3,008,420 PUMP SAFETY SWITCH Clyne A. Davis, 917 Spur St., Seminole, Okla., assigner of twenty percent to Carl Bagwell, Oklahoma City,

Okla.

Filed May 14, 1957, Ser. No. 659,052 13 Claims. (Cl. 10S- 22) This invention relates in general to ignition switches for internal combustion engines by which iare powered liquid supply line pumps and more particularly to a float actuated magneto switch controlled by a liquid in a line being pumped by an internal combustion engine having magneto ignition.

Heretofore various means have been tried for controlling the booster pump engines which are utilized in gravity fed oil lines, which are connected to well storage tanks, for automatically controlling the shut-off of the pump engine when the tank has run dry. Various electrieal and mechanical switches have heretofore been devised for controlling the ignition system of the pump motor. However, all such structures have been rather complicated Iand due to the fact that they havenumerous working parts break-downs have been very frequent. In addition, when such break-downs occur the disassembly and repair of such units has been a major problem. Further, such devices have usually been placed on the pressure or outgoing lside of the pump and therefore subject to faulty operation due to fluctuations in the pump pressure thus causing rather erratic control of the pump engine. n

Therefore, the primary object of this invention is to provide a pump safety switch which is to be installed on the suction side of a liquid booster pump which positively will cut-off the pump engine when the supply of liquid fed to the pump is exhausted.

A further object of this invention is to provide a pump safety switch which is electrically connected to the magneto of the pump engine and which has a minimum number of working parts.

A still further object of this invention is to provide a pump safety switch which may be easilsI disassembled and assembled.

Yet another object of this invention is to provide a pump safety switch which is interconnected with the suction side of the pump and which has a dampening device therein whereby fluctuations in pressure and Velocity will not be transmitted to the switch which would cause erratic operation thereof.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings for-ming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is la perspective view of the pump safety switch shown attached to a liquid supply line with the pump and the internal combustion engine which powers the pump also being shown;

FIGURE 2 is an enlarged side View of the pump safety switch housing and the pipes leading thereto;

FIGURE 3 is a still fur-ther enlarged vertical sectional view taken substantially along section line 3--3 of FIGURE 2;

FIGURE 4 is a still further enlarged horizontal sectional view taken substantially along section line 4 4 of FIGURE 3 and showing the electrical contacts of the safety switch in detail and showing in phantom lines the position of a metallic float which bridges the contacts;

FIGURE 5 is en enlarged horizontal sectional View, drawn to the same scale `as FIGURE 4 and taken along section line 5-5 of FIGURE 3;

FIGURE 6 is an exploded perspective View showing one of the electrical contacts and an insulating ring which carries the same, with the yring being shown in fragmentary form; and

FIGURE 7 is a sectional view taken substantially along section line 7-7 of FIGURE 5I showing the manner iuv which the insulating ring is attached to the electric contacts yand to the switch housing.

Referring now to the drawings in detail it will be noted that the pump safety switch, which is referred to in general by the reference numeral 10, is connected `to an oil supply line 12. The supply line 12 feeds through a booster pump 14 from whence it is pumped to an outlet 'line 16. The pump 14 is powered by an internal combustion engine 18 which is provided with magneto ignition with the magneto being designated by the numeral 29. The primary, or control of the engine magneto 20 is connected to the safety switch by means of an electrical conductor 22. The safety switch is connected to supply line 12 by means of a vertically upstanding pipe 24 which terminates in a T 26. The T 26 is provided with a vertical Iinput pipe 28 which terminates at its upper end in an L 30 and a horizontal branch 32. The branch 32 at its outer end is provided with la suitable union 34. The union 34 at the :opposite side thereof is provided with a horizontal nipple 36 which terminates in a vertical enlarged housing 38. An upper end 4f? of the housing 38 receives thereon a cap 42 which has depending therefrom, and centrally disposed in said housingv38 an air eliminator 44 which is suitably vented to the outside through a vent pipe 46. inasmuch as air eliminators are very well known in the art any further description thereof is deemed unnecessary.

The lower end of the housing 38, see in particular FIGURE 3, terminates in `a bell 48 and an outwardly extending flange 50. The flange 50 on the inner surface thereof is provided with an annular groove 52 which receives therein one side of a packing ring 54. The other side of the packing ring 54 is received in an annular groove S6 of a mating and depending flange 58. The flange 5S is secured to the flange 50 by means of through 'bolts 60. The flange 58 has formed integral therewith and depending therefrom a bell mouth 62, which in turn terminates in a cylindrical switch Contact ring 64. lmmediately below the ring 64 there has been provided a further reduction in cross sectional area in a funnel 66 which terminates in va straight nipple 68. The nipple 68 is attached to an L 470, which is attached to a drop seat check valve housing 72 by means of 1a nipple 74, the other end of the housing 72 being in communication with the T 26 through a nipple 76. The housing 72 contains therein a drop seat valve 7 8.

The ring 64, at its juncture with the funnel 66 is provided as shown best in FIGURES 5 and 7 with an inwardly extending metal flange 8G, which is suitably attached as by welding to the inner surface of the ring 64. The flange Sil is provided with a pair of lugs 82 and `84, which extend radially inward, and the purpose of which will be described hereinafter. The flange supports in overlying relation thereon an annular insulating ring 8'6, which in turn carries four upstanding electrical contacts, which are referred to in general by the reference numeral 88. The contacts S8 are disposed at increments about the ring 86. Each of the contacts 88, see FIGURE 6', is provided with a semi-cylindrical upper surface 98 and a flat lower surface 92, which has depending therefrom a threaded stud 94. The stud 94, at its juncture with the surface 92 is provided with diametrically opposed lugs 96 and 98 which engage in recesses ltiil and 102 respectively which are formed in the upper surface of the insulating ring 86 thus preventing relative rotation of the contacts when assembled with the ring. The stud 94 is received in an aperture 104 and receives on the opposite end thereof a nut 186. Two of the contacts 88, see FIGURE 4, have formed integral therewith side extending lugs 188, the bottom surfaces of such lugs being in coplanar relation with the surface 92 of the contact and which have apertures 110 extending therethrough. When the insulation ring is assembled with the flange Si), the apertures 11() are in registry with apertures in the lugs 82 and 84. Screws 112 extend therethrough which receive nuts 114 on the lower ends thereof, thus assuring excellent electrical contact and mechanical stability. The other pair of contacts are insulated away from any ground contact and are interconnected by means of an electrical connector 116 and also electrically connected to a magneto post 118 by means of a connector 120. The post 118 is insulated away from ring 64 by means of an inner Washer 122 and an outer washer 124. lt should be understood that the washers 122 and 124 are of a suitable compressible material which in addition to acting as `an insulator also provides a positive liquid seal for the post 118. The post 118 receives on the outer end thereof the magneto wire 22 and is retained within ring 64 by means of an inner nut 126 and an louter nut 128.

As will be noted in FIGURE 3, there is provided Within the safety switch 10 a free floating metallic ball 128 which serves as a positive electrical contact between the grounded pair of contacts 88 and the insulated pair of contacts when the ball is in a non-floating position.

It should be noted that Iall of the joints with the exception of the two unions, are of welded construction. However, any manner of joining the pipes may be utilized which renders a liquid tight device. The operation of the device is as follows: Assuming that the supply pipe 12 is attached to a supply tank and that the supply tank is full of oil or other liquid which is to be pumped, such liquid rises in the pipe 24 through the pipe 28 union 34 into the housing 38. When the liquid enters the housing it gradually fills the same and thus causes the float 128 to rise in the housing 38, all air being bled oft through the automatic air eliminator 44. Inasrnuch as the float 128 is no longer shorting the magneto 28 through the contact 88, the pump engine 18 may be started. During the pumping operation minor fluctuations in pressure may take place within supply line 12, however, such variations in pressure will not cause rapid rise and fall of the float 128 inasmuch as the level of the liquid within the system must go up the pipe 28 in order to get within the housing 38. Therefore, the float 128 is prevented from bobbing up and down within the housing and accidentally shorting the contacts during the middle of the pumping operation. When the supply of liquid from the tank ceases to flow into the supply line 12 the level of liquid within the housing 38 gradually diminishes, being drained off through the drop check valve, thus allowing the iioat 128 to come to rest on the contacts 88. When this occurs, the magneto is shorted through the wire 22 and the pipe system itself. Thus, the engine is not run unnecessarily after the supply tank has been exhausted.

In the event it is necessary to disassemble the safety switch for any reason the union 34 may be separated and the flanges 50 and 458 may be separated and either the entire unit may be replaced, a float may be checked or any other necessary maintenance accomplished.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed is as follows:

1. In combination, a liquid pump having a liquid supply line and a liquid discharge line connected thereto, power means drivingly connected to said pump, an electric circuit means vital to operation of and operatively connected to said power means, said circuit means including a normally open liquid level controlled switch, said switch including a vertical container disposed above and communicating at its lower end with said supply line for receiving liquid therefrom, a pair of spaced electrical contacts mounted in the lower portion of said container and connected to said circuit means for grounding the latter and rendering the power means inoperative when said contacts are bridged and for rendering the circuit means and said power means operative when the contacts are open, a metallic oat in said container vertically movable in accordance with the liquid level therein into and out of bridging engagement with lsaid contacts, damping means connecting said supply line to said container for preventing affecting of the liquid level in said container by minor pressure fluctuations produced in said supply line by pump pulses.

2. The combination of claim l wherein said damping means comprises a conduit having free and unobstructed communication with said supply line and with said container at a position above said contacts, the lower end of said container having a valve therein effecting free ilow of liquid from said supply line into the bottom of said container but obstructing and restricting the rate of return flow from the latter to the former.

3. The combination of claim 2 including a float controlled air vent means in the upper end of said container.

4. The combination of claim 1 including a float controlled air vent means in the upper end of said container.

5. The combination of claim 1 wherein said container comprises upper and lower lvertically aligned sections, the adjacent portions of said sections being laterally enlarged and providing a switch chamber therebetween, said contacts being mounted in said chamber in said lower section, coupling means detachably connecting the adjacent portions of said section in fluid tight relation.

6. The combination of claim l wherein said damping means comprises a conduit having free and unobstructed communication with said supply line and with said container at a position above said contacts, the lower end of said container having a valve therein effecting free flow of liquid from said supply line into the bottom of said container but obstructing and restricting the rate of return flow from the latter to the former, said conduit having interposed therein adjacent its connection to said container a releasable coupling.

7. The combination of claim l wherein said container comprises upper and lower vertically aligned sections, the adjacent portions of said sections being laterally enlarged and providing a switch chamber therebetween, said contacts being mounted in said chamber in said lower section, coupling means detachably connecting the adjacent portions of said section in fiuid tight relation, said damping means comprising a conduit having free and unobstructed communication with said supply line and with said container at a position above said contacts, the lower end of said container having a valve therein effecting free fl w of liquid from said supply line into the bottom of said container but obstructing and restricting the rate of return flow from the latter to the former.

8. The combination of claim 7 wherein said conduit has interposed therein adjacent its connection to said container a releasable coupling.

9. A liquid level controlled switch for an electrical circuit comprising a container, means for supplying liquid to said container, a pair of spaced electrical contacts in the lower portion of said container connected to said circuit and operative upon bridging of said contacts to ground said circuit and render it inoperative and effective when said contacts are unbridged to effect continued operability of said circuit, a metallic float movable vertically in said container above said contacts in accordance with the liquid level in the container between a lower position bridging said contacts and upper positions which are out of engagement with said contacts, damping means connected to said supply means and to said container for preventing minor pressure pulsations in said supply means for affecting the liquid level in said container, said damping means comprising a conduit having free and unobstructed communication with said supply line and with said container at a position above said contacts, the lower end of said container having a valve therein effecting free ow of liquid from said supply line into the bottom `of said container but obstructing and restricting the rate of return flow from the latter to the former,

10. The combination of claim 9 including a iloat controlled air vent means in the upper end of said container;

11. A liquid level controlled switch `for an electrical circuit comprising a container, means for supplying liquid to said container, a pair of spaced electrical contacts in the lower portion of said container connected to said circuit and operative upon bridging of said contacts to ground said circuit and render it inoperative and eiective when said contacts are unbridgcd to effect continued operability of said circuit, a metallic float movable vertically in said container above said contacts in accordance with the liquid level in the container between a lower position bridging said contacts and upper positions which are out of engagement with said contacts, damping means connected to said supply means and to said container for preventing minor pressure pulsations in said supply means for affecting the liquid level in said container, a iioat controlled air vent means in the upper end of said container.

12. A liquid level controlled switch `for an electrical circuit comprising a container, means for supplying liquid to said container, a pair of spaced electrical contacts in the lower portion of said container connected to said circuit and operative upon lbridging of said contacts to ground said circuit and render it inoperative and effective when said contacts are unbrid'ged to effect continued operability of said circuit, a metallic float movable vertically in said container above said contacts in accordance with the liquid level in the container between a lower position bridging said contacts and upper positions which are out of engagement with said contacts, damping means connected to said supply means and to said container for preventing minor pressure pulsations in said supply means for affecting the liquid ilevel in said container, said container comprising upper and lower vertically aligned sections, the adjacent portions of said sections being laterally enlarged and providing a switch chamber therebetween, said contacts being mounted in said chamber in said lower section, coupling means detachably connecting the adjacent portions of said section in uid tight relation.

13. The combination of claim 12 wherein said damping means comprises a conduit having free and unobstructed communication with said supply line and with said container at a position above said contacts, the lower end of said container having a valve therein effecting free ow of liquid from said supply line into the bottom of said container but obstructing rand restricting the rate of return ow from the latter to the former.

References Cited in the ile of this patent UNITED STATES PATENTS 1,032,896 Hagan July 16, 1912 1,083,315 Yetman Jan. 6, 1914 1,213,152 Chambers Jan. 23, 1917 1,642,434 Faunce Sept. 13, 1927 1,705,792 Vignere Mar. 19, 1929 2,483,084 `Callahan Sept. 27, 1949 2,524,274 Samuels Oct. 3, 1950 2,581,330 Patterson Jan. 1, 1952 2,634,682 Dye Apr. 14, 1953 2,661,411 Berger Dec. 1, 1953 2,733,660 Towle et al. Feb. 7, 1956 2,819,363 Narzisi Ian. 7, 1958 

